Genomic and Molecular Screenings Identify Different Mechanisms for Acquired Resistance to MET Inhibitors in Lung Cancer Cells

KIRREL promotes the proliferation of gastric cancer cells and angiogenesis through the PI3K/AKT/mTOR pathway

Anti-angiogenesis is a promising therapeutic strategy for delaying tumour progression that offers, new hope for gastric cancer targeted therapy. The purpose of this study was to investigate the precise mechanism by which Kin of IRRE-like protein 1 (KIRREL) contributes to the development of gastric cancer, particularly in terms of tumour angiogenesis. Differential expression of KIRREL in tissues and cells was detected using quantitative real-time polymerase chain reaction, western blotting and immunohistochemistry. A bioinformatics analysis was conducted to screen for the function and pathway enrichment of KIRREL in gastric cancer. Lentivirus-induced KIRREL silencing in SNU-5 cells and lentivirus-induced KIRREL overexpression in AGS cells were used to study the effect of KIRREL on the proliferation, cell cycle and angiogenesis of gastric cancer cells. Moreover, the expressions of PI3K, P-PI3K, AKT, P-AKT, mTOR, P-mTOR, HIF-1α and VEGF were also detected. Gastric cancer tissues and cells had high levels of KIRREL expression, which is associated with the proliferation, cell cycle and angiogenesis of gastric cancer cells. After silencing and overexpressing KIRREL in SNU-5 and AGS cells, respectively, the proliferation and angiogenesis of SNU-5 cells were inhibited, while the proliferation and angiogenesis of AGS cells were promoted. According to a bioinformatics analysis of the KIRREL gene, angiogenesis regulation and the PI3K/AKT pathway were highly connected. The PI3K/AKT/mTOR pathway was repressed and stimulated by KIRREL silencing and overexpression, respectively. IGF-1, an AKT agonist, and LY294002, an inhibitor, reversed the effects of KIRREL silencing and overexpression on the PI3K/AKT/mTOR pathway and on gastric cancer cell proliferation and angiogenesis. KIRREL may mediate the proliferation and angiogenesis of gastric cancer cells through the PI3K/AKT/mTOR signalling pathway. These findings could help in the further development of potential anti-angiogenesis targets.

HDAC11, an emerging therapeutic target for metabolic disorders

Histone deacetylase 11 (HDAC11) is the only member of the class IV HDAC, and the latest member identified. It is highly expressed in brain, heart, kidney and some other organs, and located in mitochondria, cytoplasm and nuclei, depending on the tissue and cell types. Although studies in HDAC11 total knockout mice suggest its dispensable features for tissue development and life, it participates in diverse pathophysiological processes, such as DNA replication, tumor growth, immune regulation, oxidant stress injury and neurological function of cocaine. Recent studies have shown that HDAC11 is also critically involved in the pathogenesis of some metabolic diseases, including obesity, diabetes and complications of diabetes. In this review, we summarize the recent progress on the role and mechanism of HDAC11 in the regulation of metabolic disorders, with the focus on its regulation on adipogenesis, lipid metabolism, metabolic inflammation, glucose tolerance, immune responses and energy consumption. We also discuss the property and selectivity of HDAC11 inhibitors and their applications in a variety of in vitro and in vivo models of metabolic disorders. Given that pharmacological and genetic inhibition of HDAC11 exerts a beneficial effect on various metabolic disorders, HDAC11 may be a potential therapeutic target to treat chronic metabolic diseases.

Fuzheng Huayu Recipe and its active compounds inhibited HBeAg production by promoting TOMM34 gene expression in HBV-infected hepatocytes

Background and aim: Fuzheng Huayu Recipe (FZHY) is a Chinese patent medicine (approval No. Z20020074) included in the national medical insurance catalogue, which is mainly used for anti-hepatic fibrosis treatment of hepatitis B virus (HBV) induced liver fibrosis and liver cirrhosis. In clinical practice, we discovered that FZHY might also have a direct anti-HBV effect on inhibiting HBeAg production, but the mechanism underlying was unclear. This study aimed to clarify the molecular mechanism of the inhibition effect of FZHY on HBeAg production.

Methods: The decrease degree of serum HBeAg titer in FZHY + entecavir (ETV) group patients were analyzed through clinical data. C57BL/6N-Tg (1.28HBV)/Vst HBV transgenic mice were used for in vivo experiments. HepG2. 2.15 cells (wild-type HBV replication cells) were used for in vitro experiments.

Results: The clinical study results showed that the decrease degree of serum HBeAg titer in FZHY+ETV group was significantly higher than that in ETV group after 48 weeks treatment. In vivo experiments results showed that FZHY could significantly reduce the serum HBeAg titer in HBV transgenic mice, and promote HBeAg seroconversion. In vitro experiments results showed that FZHY could reduce HBeAg titer dependently, but it did not significantly inhibit the expression of HBsAg and HBV-DNA. Further cell experiments in vitro discovered that TOMM34 might be the key target for FZHY to inhibit HBeAg production. The subsequent pharmacological screening experiment of 20 active compounds in FZHY showed that quercetin, baicalin and cordycepin could promote the expression of TOMM34 gene and reduce the production of HBeAg.

Conclusion: In conclusion, FZHY and its active compounds quercetin, baicalin and cordycepin could inhibit HBeAg production by promoting the expression of TOMM34 gene in HBV-infected hepatocytes.

Sequential Capecitabine/Temozolomide and Sunitinib Treatment in Patients With Metastatic Well-Differentiated Grade 1/Grade 2 Pancreatic Neuroendocrine Tumors

OBJECTIVE

The role of alternate sequential administration of sunitinib and capecitabine/temozolomide (CAPTEM) in metastatic pancreatic neuroendocrine tumors (PanNETs) remains unexplored. We thus aimed to analyze the efficacy and tolerability of this strategy in advanced grade 1/grade 2 PanNETs.

METHODS

In total, data of 43 patients with metastatic PanNET were collected from a real-world database of a cancer center. Twenty-four patients were treated with sunitinib followed by CAPTEM (group 1), and 19 patients were treated with CAPTEM followed by sunitinib (group 2).

RESULTS

Twenty-three patients were treated with first-line sunitinib or CAPTEM, and 20 patients were pretreated with somatostatin analog (SSA) or SSA in combination with transcatheter arterial chemoembolization. The objective response rate with first-line treatment was similar in both groups, whereas that with second-line treatment was higher in group 1 than in group 2, albeit with no significant differences (21.1% vs 5.3%, respectively; P = .205). Median progression-free survival (mPFS) for first-line and second-line treatments did not differ between the 2 groups (11 and 12 months vs 12 and 8 months, respectively). Following subgroup analyses, treatment with first-line sunitinib and sunitinib after pretreated SSA had a longer mPFS than that with second-line sunitinib after CAPTEM (11 months vs 8 months, respectively; P = .046), whereas treatment with first-line CAPTEM and CAPTEM after pretreated SSA had an mPFS similar to that of second-line CAPTEM after sunitinib treatment. CAPTEM and sunitinib had similar tolerability.

CONCLUSION

Alternating sunitinib and CAPTEM were well tolerated and associated with similar mPFS in grade 1/grade 2 PanNETs. However, larger prospective studies are required to investigate the efficacy of alternate sequential therapies for metastatic PanNET.

miR-17-3p promotes the proliferation of multiple myeloma cells by downregulating P21 expression through LMLN inhibition

Multiple myeloma (MM), a hematological malignancy, has a poor prognosis and requires an invasive procedure. Reports have implicated miRNAs in the diagnosis, treatment and prognosis of hematological malignancies. In our study, we evaluated the expression profiles of miR-17-3p in plasma and bone marrow mononuclear cells of monoclonal gammopathy of undetermined significance (MGUS) and MM patients and healthy subjects. The results showed that the plasma and mononuclear cell expression levels of miR-17-3p in MM patients were higher than those in MGUS patients and normal controls. In addition, the expression of miR-17-3p was positively correlated with diagnostic indexes, such as marrow plasma cell abundance and serum M protein level, and positively correlated with the International Staging System stage of the disease. Receiver operating characteristic curve analysis suggested that miR-17-3p might be a diagnostic index of MM. Moreover, miR-17-3p regulated cell proliferation, apoptosis and the cell cycle through P21 in MM cell lines and promoted MM tumor growth in vivo. Furthermore, we predicted and verified LMLN as a functional downstream target gene of miR-17-3p. Negatively regulated by miR-17-3p, LMLN inhibits MM cell growth, exerting a tumor suppressive function through P21. Taken together, our data identify miR-17-3p as a promising diagnostic biomarker for MM in the clinic and unveil a new miR-17-3p-LMLN-P21 axis in MM progression.

Capmatinib for patients with non-small cell lung cancer with MET exon 14 skipping mutations: A review of preclinical and clinical studies

The mesenchymal-epithelial transition (MET) receptor tyrosine kinase binds the hepatocyte growth factor to activate downstream cell signaling pathways involved in cell proliferation, survival, and migration. Several genetic mechanisms can result in an aberrant activation of this receptor in cancer cells. One such activating mechanism involves the acquisition of gene mutations that cause MET exon 14 skipping (METex14) during mRNA splicing. Mutations leading to METex14 are found in approximately 3-4% of patients with non-small cell lung cancer (NSCLC). Accumulating evidence suggests that METex14 is a true, independent oncogenic driver in NSCLC, as well as being an independent prognostic factor for poorer survival in patients with NSCLC. The successes of target therapies have relied on improved understanding of the genetic alterations that lead to the dysregulation of the molecular pathways and more advanced molecular diagnostics. Multiple efforts have been made to target the MET pathway in cancer; however, real clinical progress has only occurred since the emergence of METex14 as a valid biomarker for MET inhibition. Capmatinib is a highly potent and selective type Ib inhibitor of MET. Following preclinical demonstration of activity against MET-dependent cancer cell line growth and MET-driven tumor growth in xenograft models, data from a phase 1 clinical trial showed an acceptable safety profile of capmatinib and preliminary evidence of efficacy in patients with MET-dysregulated NSCLC. The multicohort GEOMETRY mono-1 phase 2 trial reported objective response rates of 68% and 41% in treatment-naïve and in pre-treated patients with METex14 advanced NSCLC, respectively. These results have supported the approval of capmatinib by the US Food and Drug Administration for patients with metastatic NSCLC harboring METex14.

Hypoxic bone marrow mesenchymal cell-extracellular vesicles containing miR-328-3p promote lung cancer progression via the NF2-mediated Hippo axis

Lung cancer is the most aggressive tumour afflicting patients on a global scale. Extracellular vesicle (EV)-delivered microRNAs (miRs) have been reported to play critical roles in cancer development. The current study aimed to investigate the role of hypoxic bone marrow mesenchymal cell (BMSC)-derived EVs containing miR-328-3p in lung cancer. miR-328-3p expression was determined in a set of lung cancer tissues by RT-qPCR. BMSCs were infected with lentivirus-mediated miR-328-3p knock-down and then cultured in normoxic or hypoxic conditions, followed by isolation of EVs. Following ectopic expression and depletion experiments in lung cancer cells, the biological functions of miR-328-3p were analysed using CCK-8 assay, flow cytometry and Transwell assay. Xenograft in nude mice was performed to test the in vivo effects of miR-328-3p delivered by hypoxic BMSC-derived EVs on tumour growth of lung cancer. Finally, the expression of circulating miR-328-3p was detected in the serum of lung cancer patients. miR-328-3p was highly expressed in EVs derived from hypoxic BMSCs. miR-328-3p was delivered to lung cancer cells by hypoxic BMSC-derived EVs, thereby promoting lung cancer cell proliferation, invasion, migration and epithelial-mesenchymal transition. miR-328-3p targeted NF2 to inactivate the Hippo pathway. Moreover, EV-delivered miR-328-3p increased tumour growth in vivo. Additionally, circulating miR-328-3p was bioactive in the serum of lung cancer patients. Taken together, our results demonstrated that hypoxic BMSC-derived EVs could deliver miR-328-3p to lung cancer cells and that miR-328-3p targets the NF2 gene, thereby inhibiting the Hippo pathway to ultimately promote the occurrence and progression of lung cancer.

SRC and PIM1 as potential co-targets to overcome resistance in MET deregulated non-small cell lung cancer

Background

The role of MET alterations in non-small cell lung cancer (NSCLC) is increasing and several targeted agents are under evaluation. MET exon 14 skipping mutations and MET amplifications are associated with potential sensitivity to MET inhibition, though resistance mechanisms are emerging. In MET addicted cells, MET inhibition leads to activation of proviral integration site for Moloney murine leukemia virus-1 (PIM1). PIM1 and proto-oncogene tyrosine-protein kinase Src (SRC) can regulate the expression of receptor tyrosine kinases (RTKs), potentially inducing resistance to MET inhibition through cross-activation.

Methods

We evaluated the activity of class I–II MET inhibitors, the SRC inhibitor dasatinib, and pan-PIM inhibitors in four MET addicted cell lines. We assessed the effect of the dual MET/PIM and MET/SRC inhibition on cell viability and at the protein level. We evaluated RNA expression profiles of the cell lines. Advanced NSCLCs were also screened for MET alterations.

Results

All cell lines were sensitive to class I–II MET inhibitors. All cell lines were resistant to single PIM and SRC inhibition. Dual MET/PIM inhibition was synergistic or additive in MET amplified cell lines and dual MET/SRC inhibition was highly synergistic in all MET addicted cell lines. The addition of an SRC inhibitor partially prevents the RTKs cross-activation. MET alterations were found in 9 out of 97 evaluable samples (9.3%); median overall survival in MET altered patients was 5 months (95% CI, 3 m–NA).

Conclusions

We identified a potential role of PIM inhibition in MET amplified tumors and of SRC inhibition in MET addicted tumors. Potential applications of this new treatment strategy warrant further evaluation.

HDAC11: a rising star in epigenetics

Epigenetic mechanisms, such as acetylation, methylation, and succinylation, play pivotal roles in the regulation of multiple normal biological processes, including neuron regulation, hematopoiesis, bone cell maturation, and metabolism. In addition, epigenetic mechanisms are closely associated with the pathological processes of various diseases, such as metabolic diseases, autoimmune diseases and cancers. Epigenetic changes may precede genetic mutation, so research on epigenetic changes and regulation may be important for the early detection and diagnosis of disease. Histone deacetylase11 (HDAC11) is the newest member of the histone deacetylase (HDAC) family and the only class IV histone deacetylase. HDAC11 has different expression levels and biological functions in different systems of the human body and is among the top 1 to 4% of genes overexpressed in cancers, such as breast cancer, hepatocellular carcinoma and renal pelvis urothelial carcinoma. This article analyzes the role and mechanism of HDAC11 in disease, especially in tumorigenesis, in an attempt to provide new ideas for clinical and basic research.

Overexpression of kin of IRRE-Like protein 1 (KIRREL) as a prognostic biomarker for breast cancer

OBJECTIVES

The purpose of this study was to investigate the expression of Kin of IRRE-Like Protein 1 (KIRREL) and its clinicopathologic significance in breast cancer.

MATERIALS AND METHODS

The mRNA and protein expressions of KIRREL in fresh breast cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by western blot analysis (n = 24) and RT-qPCR (n = 48). KIRREL was detected by immunohistochemistry (IHC) using breast cancer tissue microarrays (TMAs) in 302 patients. The prognostic roles and clinicopathologic significances in breast cancer were statistically analyzed.

RESULTS

Compared with para-carcinoma tissues, KIRREL mRNA and protein were overexpressed in breast cancer tissues. Immunohistochemical results showed that the high expression rate of KIRREL staining in breast cancer was 43.7% (132/302). Moreover, Expression of KIRREL was significantly correlated with Her2 status and survival outcomes of patients. Patients with both positive expression of KIRREL showed shorter overall survival (OS) and progression free survival (PFS). Additionally, Cox multivariate survival analysis revealed that KIRREL level, age, primary tumor size, tumor stage and distant metastasis were the independent parameter predicting the prognosis of breast cancer patients.

CONCLUSIONS

KIRREL was overexpressed in breast cancer and the overexpression of KIRREL could serve as an independent predictor of poor prognosis in breast cancer patients.

A Single-Step, High-Dose Selection Scheme Reveals Distinct Mechanisms of Acquired Resistance to Oncogenic Kinase Inhibition in Cancer Cells

Despite the remarkable clinical efficacy demonstrated by molecularly targeted cancer therapeutics, the benefits are typically temporary due to the emergence of acquired drug resistance. This has spurred a massive effort by the cancer research community to identify mechanisms used by cancer cells to evade treatment. Among the various methodologies developed and employed to identify such mechanisms, the most commonly used approach has been to model acquired resistance by exposing cancer cells in culture to gradually increasing concentrations of drug over an extended period of time. Here, we employed a less commonly used variation on this approach, wherein resistant cells are selected by immediately exposing cancer cells to a continuous, high concentration of drug. Using this approach, we isolated clones representing three distinct mechanisms of resistance to inhibition of MET kinase activity from a single clonally derived cancer cell line. The emergent clones had acquired resistance through engagement of alternative receptor tyrosine kinases either through upregulation of FGF3 or HBEGF or increased MAPK signaling through an activating V600E mutation in BRAF. Importantly, these mechanisms were not identified using the conventional "ramp-up" approach in previous studies that employed the same cell line. These results suggest that the particular nature of the selection scheme employed in cell culture modeling studies can determine which potential resistance mechanisms are identified and which ones may be missed, highlighting the need for careful consideration of the specific approach used to model resistance in cultured cells. SIGNIFICANCE: Through modeling resistance to MET kinase inhibition in cultured cancer cells using single-step, high-dose selection, these findings highlight that the specific nature of the selection protocol impacts which resistance mechanisms are identified.See related commentary by Floros et al., p. 25.

Antitumor Activity of DFX117 by Dual Inhibition of c-Met and PI3Kα in Non-Small Cell Lung Cancer

Aberrant activation of hepatocyte growth factor (HGF)/c-Met signaling pathway caused by gene amplification or mutation plays an important role in tumorigenesis. Therefore, c-Met is considered as an attractive target for cancer therapy and c-Met inhibitors have been developed with great interests. However, cancers treated with c-Met inhibitors inevitably develop resistance commonly caused by the activation of PI3K/Akt signal transduction pathway. Therefore, the combination of c-Met and PI3Kα inhibitors showed synergistic activities, especially, in c-Met hyperactivated and PIK3CA-mutated cells. In our previous study, we rationally designed and synthesized DFX117(6-(5-(2,4-difluorophenylsulfonamido)-6-methoxypyridin-3-yl)-N-(2-morpholinoethyl) imidazo[1,2-a]pyridine-3-carboxamide) as a novel PI3Kα selective inhibitor. Herein, the antitumor activity and underlying mechanisms of DFX117 against non-small cell lung cancer (NSCLC) cells were evaluated in both in vitro and in vivo animal models. Concurrent targeted c-Met and PI3Kα by DFX117 dose-dependent inhibited the cell growth of H1975 cells (PIK3CA mutation and c-Met amplification) and A549 cells (KRAS mutation). DFX117 subsequently induced G0/G1 cell cycle arrest and apoptosis. These data highlight the significant potential of DFX117 as a feasible and efficacious agent for the treatment of NSCLC patients.

MET Inhibition in Non-Small Cell Lung Cancer

Cancer treatment paradigms have evolved over recent years with an emphasis on personalised medicine. Targeted agents are being used to improve treatment outcomes and quality of life. For the treatment of non-small cell lung cancer, several agents with unique genetic and epigenetic targets are available. To this extent, mesenchymal–epithelial transition (MET), a heterodimer receptor tyrosine kinase involved in embryogenesis and organogenesis, has been investigated as a potential target for biological agents. MET dysregulation can occur via different mechanisms and trigger tumourigenesis and disease spread. Besides driving the oncogenic dependence of cells, MET is also involved in acquired resistance to epidermal growth factor receptor inhibitors. As such, many small molecule kinase inhibitors and antibodies have been developed or are currently in different phases of clinical trials to counteract the MET-induced neoplastic activity. Some of these agents are selective while others are nonselective with multiple other potential targets. This article aims to present an overview of biological functioning of MET, its role in oncogenesis and resistance to treatment, and clinical studies evaluating MET inhibitors for treatment of non-small cell lung cancer.

Examination of Independent Prognostic Power of Gene Expressions and Histopathological Imaging Features in Cancer

Cancer prognosis is of essential interest, and extensive research has been conducted searching for biomarkers with prognostic power. Recent studies have shown that both omics profiles and histopathological imaging features have prognostic power. There are also studies exploring integrating the two types of measurements for prognosis modeling. However, there is a lack of study rigorously examining whether omics measurements have independent prognostic power conditional on histopathological imaging features, and vice versa. In this article, we adopt a rigorous statistical testing framework and test whether an individual gene expression measurement can improve prognosis modeling conditional on high-dimensional imaging features, and a parallel analysis is conducted reversing the roles of gene expressions and imaging features. In the analysis of The Cancer Genome Atlas (TCGA) lung adenocarcinoma and liver hepatocellular carcinoma data, it is found that multiple individual genes, conditional on imaging features, can lead to significant improvement in prognosis modeling; however, individual imaging features, conditional on gene expressions, only offer limited prognostic power. Being among the first to examine the independent prognostic power, this study may assist better understanding the "connectedness" between omics profiles and histopathological imaging features and provide important insights for data integration in cancer modeling.

Overexpression of heat shock protein HSP90AA1 and translocase of the outer mitochondrial membrane TOM34 in HCV-induced hepatocellular carcinoma: A pilot study

OBJECTIVE

Identification of new molecular markers to enhance early diagnosis, prognosis and/or treatment of hepatocellular carcinoma (HCC) is a need. TOM34 (34 kDa-translocase of the outer mitochondrial membrane) protein expression deregulation has demonstrated to be involved in the growth of many cancers. Here, we aimed at evaluating serum TOM34 and some heat shock proteins (HSPA4, HSPA1B, and HSP90AA1) expressions in hepatitis C virus (HCV)-related cirrhosis and HCV-induced HCC relative to controls and correlating these expressions to the clinicopathological data.

METHODS

Serum specimens were collected from 90 patients with HCV associated complications (30 cirrhotic, 30 early HCC and 30 late HCC) and 60 controls. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed for relative quantification of the four target genes using the Livak method. In silico network analysis was also executed to explore the contribution of the genes in liver cancer.

RESULTS

The serum TOM34 and HSP90AA1 transcripts were significantly upregulated in HCC patients compared to cirrhotic ones with more up-regulation in late HCC patients. Receiver operating characteristic analysis showed the optimum cutoff value of 0.625 corresponding to 71.7% sensitivity and 56.7% specificity, and an area under the curve (AUC) of 0.705 to discriminate HCC from cirrhotic groups (P = .002). In multivariate analysis, ordination plot showed obvious demarcation between the study groups caused by the higher levels of TOM34 among other variables.

CONCLUSIONS

TOM34 and its partner HSP90AA1 might be used as a potential biomarker for monitoring HCV-induced HCC progression in the Egyptian population. Future large-scale validation studies are warranted.

Status of Agents Targeting the HGF/c-Met Axis in Lung Cancer

Hepatocyte growth factor (HGF) is the ligand for the tyrosine kinase receptor c-Met (Mesenchymal Epithelial Transition Factor also known as Hepatocyte Growth Factor Receptor, HGFR), a receptor with expression throughout epithelial and endothelial cell types. Activation of c-Met enhances cell proliferation, invasion, survival, angiogenesis, and motility. The c-Met pathway also stimulates tissue repair in normal cells. A body of past research shows that increased levels of HGF and/or overexpression of c-Met are associated with poor prognosis in several solid tumors, including lung cancer, as well as cancers of the head and neck, gastro-intestinal tract, breast, ovary and cervix. The HGF/c-Met signaling network is complex; both ligand-dependent and ligand-independent signaling occur. This article will provide an update on signaling through the HGF/c-Met axis, the mechanism of action of HGF/c-Met inhibitors, the lung cancer patient populations most likely to benefit, and possible mechanisms of resistance to these inhibitors. Although c-Met as a target in non-small cell lung cancer (NSCLC) showed promise based on preclinical data, clinical responses in NSCLC patients have been disappointing in the absence of MET mutation or MET gene amplification. New therapeutics that selectively target c-Met or HGF, or that target c-Met and a wider spectrum of interacting tyrosine kinases, will be discussed.

Deep analysis of acquired resistance to FGFR1 inhibitor identifies MET and AKT activation and an expansion of AKT1 mutant cells

The development of acquired resistance (AR) to tyrosine kinase inhibitors (TKIs) of FGFR1 activation is currently not well understood. To gain a deeper insight into this matter in lung cancer, we used the FGFR1-amplified DMS114 cell line and generated multiple clones with AR to an FGFR1-TKI. We molecularly scrutinized the resistant cells, using whole-exome sequencing, RNA sequencing and global DNA methylation analysis. Our results show a de novo activation of AKT and ERK, and a reactivation of mTOR. Furthermore, the resistant cells exhibited strong upregulation and activation of MET, indicating crosstalk between the FGFR1 and MET axes. The resistant cells also underwent a global decrease in promoter hypermethylation of the CpG islands. Finally, we observed clonal expansion of a pre-existing change in AKT1, leading to S266L substitution, within the kinase domain of AKT. Our results demonstrate that AR to FGFR1-TKI involves deep molecular changes that promote the activation of MET and AKT, coupled with common gene expression and DNA methylation profiles. The expansion of a substitution at AKT1 was the only shared genetic change, and this may have contributed to the AR.

MET-Oncogenic and JAK2-Inactivating Alterations Are Independent Factors That Affect Regulation of PD-L1 Expression in Lung Cancer

Purpose: The blockade of immune checkpoints such as PD-L1 and PD-1 is being exploited therapeutically in several types of malignancies. Here, we aimed to understand the contribution of the genetics of lung cancer to the ability of tumor cells to escape immunosurveillance checkpoints.Experimental Design: More than 150 primary non-small cell lung cancers, including pulmonary sarcomatoid carcinomas, were tested for levels of the HLA-I complex, PD-L1, tumor-infiltrating CD8⁺ lymphocytes, and alterations in main lung cancer genes. Correlations were validated in cancer cell lines using appropriate treatments to activate or inhibit selected pathways. We also performed RNA sequencing to assess changes in gene expression after these treatments.Results:MET-oncogenic activation tended to associate with positive PD-L1 immunostaining, whereas STK11 mutations were correlated with negative immunostaining. In MET-altered cancer cells, MET triggered a transcriptional increase of PD-L1 that was independent of the IFNγ-mediated JAK/STAT pathway. The activation of MET also upregulated other immunosuppressive genes (PDCD1LG2 and SOCS1) and transcripts involved in angiogenesis (VEGFA and NRP1) and in cell proliferation. We also report recurrent inactivating mutations in JAK2 that co-occur with alterations in MET and STK11, which prevented the induction of immunoresponse-related genes following treatment with IFNγ.Conclusions: We show that MET activation promotes the expression of several negative checkpoint regulators of the immunoresponse, including PD-L1. In addition, we report inactivation of JAK2 in lung cancer cells that prevented the response to IFNγ. These alterations are likely to facilitate tumor growth by enabling immune tolerance and may affect the response to immune checkpoint inhibitors. Clin Cancer Res; 24(18); 4579-87. ©2018 AACR.

RNA-sequencing dissects the transcriptome of polyploid cancer cells that are resistant to combined treatments of cisplatin with paclitaxel and docetaxel

Overcoming chemoresistance will prevent cancer relapse and contribute to clinical chemotherapy. In order to explore the underlying mechanism of chemoresistance, we firstly incubated cancer cells with a combination of cisplatin + paclitaxel (C + P) or cisplatin + paclitaxel + docetaxel (C + P + D) to mimic the treatment of cancer therapy in the laboratory. We found that polyploidy is a recurring strategy that cells adopt in response to cisplatin-based treatments. RNA-sequencing was performed to identify differentially expressed genes (DEGs) that may contribute to drug resistance. 4830 and 5518 DEGs were discovered in C + P and C + P + D resistant cells, respectively, and 4384 (73.40%) genes were shared. Possible drug resistance genes like Atg14, Abcb1b, Tbx2, Slc2a9, Slc10a3 and Slc22a18 were up-regulated while Foxm1, Bcl2, Brca1, Chek1, Hiatl1 and Abcb9 were down regulated. Genes involved in the pathways of p53 signaling, lysosomes and apoptosis were up-regulated, and in contrast, genes in the cell cycle, DNA replication, and mismatch repair pathways were down-regulated. Moreover, representative proteins relative to DEGs were examined to validate the results of RNA-seq and RT-PCR. Taken together, these results will contribute to revealing the mechanism of chemoresistance and discovering potential prognostic factors for cancer medication.

Overexpression of Kin of IRRE-Like Protein 1 (KIRREL) in Gastric Cancer and Its Clinical Prognostic Significance

Background

The aim of this study was to examine the expression level of IRRE-like protein 1 (KIRREL) in gastric cancer (GC) and to explore its prognostic significance.

Material/Methods

Bioinformatics methods were used to predict the differential expression levels of KIRREL mRNA in GC and normal gastric tissues by mining cancer-related databases (TCGA and Oncomine). Immunohistochemistry was done to verify the KIRREL protein expression levels in 71 cases of GC tissues combined with matched normal tissues. The relationship between clinicopathologic parameters and KIRREL differential expression levels in GC was investigated by the chi-square test. Kaplan-Meier univariate and Cox multivariate survival analyses were performed to explore the prognostic significance of KIRREL expression in GC patients.

Results

TCGA and GEO data analyses showed that KIRREL mRNA expression level was remarkably higher in GC than that in normal gastric tissues (both P<0.05). KIRREL mRNA levels were dramatically increased from stage I to stage IV (P=0.037). Immunohistochemical results showed that the high positive rate of KIRREL staining in GC was 61.97% (44/71). Moreover, GC patients with KIRREL mRNA or protein high levels had significantly shorter overall survival times than those with KIRREL mRNA or low protein levels (All P<0.05). Additionally, Cox multivariate survival analysis revealed that KIRREL differential expression levels (low vs. high) were the only independent parameter predicting the prognosis of GC patients (P=0.000).

Conclusions

KIRREL was overexpressed in GC and the overexpression of KIRREL could serve as an independent predictor of poor prognosis in GC patients.

Emerging uses of biomarkers in lung cancer management: molecular mechanisms of resistance

Management of patients with advanced non-small cell lung cancer (NSCLC) has recently been transformed by molecularly targeted and immunotherapeutic agents. In patients with EGFR/ALK/ROS mutated NSCLC, first line molecular therapy is the standard of care. Moreover, immune checkpoint inhibitors are revolutionary treatment options for advanced NSCLC and are now the standard of care in front-line or later line settings. Both classes of agents have led to improved patient outcomes, however, primary resistance and development of acquired resistance to both targeted and immunotherapeutic agents is commonly observed, limiting the use of these agents in clinical settings. In this review, we will discuss the most recent advances in understanding the mechanisms of primary and acquired resistance, progress in the spectrum of assays detecting causative molecular events and the development of new generations of inhibitors to overcome acquired resistance.

Tracking MET de-addiction in lung cancer: A road towards the oncogenic target

The discovery of druggable oncogenic drivers (i.e. EGFR and ALK), along with the introduction of comprehensive tumor genotyping techniques into the daily clinical practice define non-small-cell lung cancer (NSCLC) asa group of heterogeneous diseases, requiring a context-personalized clinico-therapeutical approach. Among the most investigated biomarkers, the MET proto-oncogene has been extensively demonstrated to play a crucial role throughout the lung oncogenesis, unbalancing the proliferation/apoptosis signaling and influencing the epithelial-mesenchymal transition and the invasive phenotype. Nevertheless, although different mechanisms eliciting the aberrant MET-associated oncogenic stimulus have been detected in lung cancer (such as gene amplification, increased gene copy number, mutations and MET/HGF overexpression), to date no clinically impactful results have been achieved with anti-MET tyrosine kinase inhibitors and monoclonal antibodies in the context of an unselected or MET enriched population. Recently, MET exon 14 splicing abnormalities have been identified asa potential oncogenic target in lung cancer, able to drive the activity of MET inhibitors in molecularly selected patients. In this paper, the major advancement and drawbacks of MET history in lung cancer are reviewed, underlying the renewed scientific euphoria related to the recent identification of MET exon 14 splicing variants asan actionable oncogenic target.